Catalysts are important components of many chemical manufacturing processes, and may typically be used to accelerate the rate of the reaction in question and/or to increase the selectivity or efficiency towards the desired product(s). Utilized in connection with many reactions, catalysts find particular advantageous use in the epoxidation of olefins, a process of significant commercial importance in the commodity chemical business. In epoxidation reactions, a feed containing at least the olefin and oxygen is contacted with a catalyst causing the formation of the corresponding olefin oxide.
One example of an olefin epoxidation of particular commercial importance is the epoxidation of alkylenes, or mixtures of alkylenes, and this epoxidation reaction in particular can rely upon high performing catalysts in order to be commercially viable. Typically, catalysts used in alkylene epoxidation comprise a catalytic species deposited on a suitable support/carrier alone or in combination with one or more promoters.
Those of skill in the art have actively sought improvements in the efficiency and/or activity of epoxidation catalysts for some time, since, on a commercial scale, even slight, e.g., 1%, increases in selectivity can reduce the operating costs associated with the epoxidation processes, substantially.
Research in this area has been wide ranging, and improvements that may provide the catalysts with increased efficiency and/or an extended useful life have been sought in the areas of components of the catalyst, e.g., carriers, promoters, and catalytic species, methods of making the catalyst and even the epoxidation processes themselves. However, it is often the case that adjustments in one or more of these may result in an improvement in one of catalyst efficiency, activity, or lifetime while yet resulting in a concurrent decrement in another. Or, any such adjustments may require conditions that cannot be produced within the epoxidation process, or if reproducible therewithin, require a reduction, or complete shut-down, in the production of the epoxidation product.
Desirably, methods would be provided that could be utilized to enhance the efficiency and/or activity of such epoxidation catalysts. Any such methods would be particularly beneficial if they could provide such enhancements over the lifetime of the catalyst, and in particular, if they could be utilized in situ, i.e., while the catalyst is in place, and/or being used in an epoxidation reaction.